Floor sanding edger



w; P. HILGER FLOOR SANDING EDGER Filed Oct. 9, 1946 PIE. 1

f as 42 43 40 3o PIE 3 IN V EN TOR.

ILLIAM RHILGER BY ATToR EY Patented Oct. 4, 1 949 girlie s-rA'rs-s Z ()FFICE FLOOR- SANDING EDGER William P. Hilger, st. cloud; Minn.

Application October 9, 1946-, Serial No.- 702,229

(CL v 5 1.-19-7 1.Glaim. 1-.

My'inventiom relates to an. improvement in the'flo'or'sanding edger set forth in myrapplication; Serial No. 671,752, filed on May 23, 1946, and which is.-providedwith an edgerconstruction employing a fiexiblef disk of reinforced rubber which enablesithe edger. to operate fully up to the baseboard mouldings, room corners, and elsewhere, said-improvement being in the means of attaching thesandpaper disk.

In the use ofsanding devices, as heretofore practiced, the :surface of the floor which had become defective or unsatisfactory either from warping of the boards to make that suriaceuneven or from damage to the finish of the surface, is removed by a floor: sanding. operation. operation, whether by a standard sanding machine or. a sandingedger, embodies the application ofa rapidly moving sheet of' sandpaper to the sufa'ce to-be reconditioned, and in the case of sanding edgers thesandpaper: is: applied" for that purpose to a rotatingdisk.

The floor sanding disk of this. invention is especially dapted to b'e'employedasfa sanding edger and the sanding disk -is capable of: operating fully up. to the: baseboard moulding, the room corners; and elsewhere.

It has been found that'inlusing the floonsandingedger' set forthinmy application,iserial N0.

67l;'7-52-, filed May 23,1946, there is a constant tendency for' the bolt'having' its. head engaging thegrits of the rotating sandpaper. both towear the head'and to tighten up. Since the sandpaper has to be frequently changed, thistightening produces a quite-serious:condition.. Even when it is found at times that it is almost impossible to-move' -the"bolt--and loosen the sandpaper to get it out and to make the change. Furthermore, the loosening'oftheflaringiace of the bolt head which contacts the sandpaper grits directly, tends Y to seriously wear that surface and. finallyrender the bolt inoperative.

I have discovered a simple and effective means to remedy the difficulty of the bolt carriedby the disk being tightened by usual-or any unusual l forces or stressestransmitted to the disk of the fioorisanding edger. when it is sanding adefective floor.

A threadedboltassembly of simple and Fefii'cient design provided. withv afirst element capable of being moved relatively. to a second portionais employed for securing the sandpaper disk to the rubber pad. When the disk is rotated with the pad and sandpaper disk on its face under ordinary operating conditions, the first element of This the fastening-bolt does'have a wrench socket i the detaileddescription of'the. device.

2. thefastening bolt assembly which contacts the grit surface of the sandpaperwill remain in fixed position against that surface, and if it rotates at'all,. will:rotate-oni-the second element, thereby preventingany excessive tightening. And since -the-second element of the fastening assembly contacts' onlythe metal of the first element, it will not tighten to an undesired degree, and it can-be readily loosenedifor changing sandpaper disk-s.

Itisthe principal objectof myinvention, therefore, to provide means for attaching the sandpaper disk to the sandingzdiskof'a floor sander or floor sanding-edger, such thatthe attaching means will not be sotightened as to'be diflicult orimpossible-ofiremoving, and such that the grit of the sandpaper itself willnot tear *or wear the I contacting .face; of the :sandpaper disk.

Itis an object. of my invention to provide a means of securingsandpaper to a sanding disk -of:a floor. sanding edger and the securing means, Y comprising two. elements adapted to=be moved 'relativelyto each other to. prevent undue tighteningof the-fastening bolt and wear. of the inner :-surface-thereof against the grit surface of the sandpaper.

Itis. another object of my invention to provideinaxfioorsanding edger an attaching means fora sanding'disk which normally maintains the sandpaper in: operative relationship relative to the. sanding disk. and the floor, but which prevents binding'. between the attaching means and theisanding disk, thus reducing or-substantially eliminating (the tightening.

'Itzisestill another object ofmy. invention to providean efiicient, yet simple holding means, for

maintaininggthe sandpaper in: its propenoperathe condition under" all circumstances on the sandingtdisk'of; afioor sanding edger.

.Otherrandxiurther objects will appear from 'Fig...1;isa sectional view of-lthefloor sanding device;- disclosing the sanding i disk secured 'to' a rotatingimem'ber.

Ei'g. 2' is a sectional .view of the securing means which: maintains the sandpaper in: operative -relationshipswith the sanding disk.

Figs 3i-israiplan viewof thenovel holding means. Referring in. detail to the: drawings, a base member. ld ha's depending flanges lzand M at '=it's.-'opposed sides.. There are flange members It and. i8 depending-from the base-"m; which are shorter in length than flanges l2 and It, being spaced inwardly of the flanges l2 and 14. There are flange members (not shown) at both ends 3 of the base uniting the side flanges l2 and I4 with each other. There are also flanges at both ends of the device for uniting the flanges I6 and I6 to each other. A plate 20 is secured throughout its extent upon the bottom edegs of flanges l3, l3 and the end flanges (not shown). The plate 20 is thereby secured in air-tight relationship by appropriate means to the bottom edges of the flanges I6 and I8 and the end flanges (not shown), forming a sealed chamber 22. This chamber 22 houses a large V-pulley 24 having a hub 26, which is removably held upon antifriction bearings 28 by means of a plate 39 held upon the hub 26 by means of screws 32. The hub 26 has removably secured thereto a sanding edger disk 34 as shown in Fig. 1 of the drawing.

The sanding disk 34 comprises a body portion of rubber having reinforcing non-stretchable layers of materials, such as canvas 36 vulcanized into said body portion. These reinforcing strips 36 are to prevent the disk 34 from stretching when the disk 34 is being rotated for sanding a floor.

The body Of the disk 34 is dished or convexed downwardly toward the surface of the floor which is to be engaged by the disk. There is a recess or depressed annular portion 38 in the under-side of the central portion of the disk body and is adapted to receive the broad head of the threaded bolt assembly 49. A threaded shank 41 passes through an opening 42 in the central portion of the disk 34 having a frust-o-cone-shaped wall 43. The shank 41 is secured in a threaded openin 4? in the plate 30 and which holds upon the face of the disk opposed to the surface of the floor, a suitable sheet of sandpaper 44, thus replaceably secured to the outer face of the sanding disk or pad 34. The sandpaper sheet 44 will, of course, be held firmly in contact with the floor surface between it and the lower surface of the sanding pad during operation of the machine.

The threaded bolt assembly 49 comprises a substantially solid frusto-cone-shaped member 46 having a threaded shank 41 at its upper end which is adapted to be passed through the center of the sanding disk and screwed into the plate 30 as indicated at 46. A second member 48 is provided with an annular flange 50 and has an external frusto-cone-shaped surface 5| which continues in a surface 53 on the upper side of the annular flange 50. The combined frusto-coneshaped surface 48 and the annular surface 53 engage the sandpaper sheet 44 and hold it against the frusto-cone-shaped wall 43 and within the depressed annular portion 38, as clearly shown in Fig. 1. The member 48 is hollow and also has a frusto-cone-shaped inner surface 53. The solid frusto-cone-shaped member 46 has a frusto-coneshaped surface 55 engageable when the parts are assembled with a correspondingly shaped and proportioned inner frusto-cone-shaped surface 56 of the member 48, all as shown in Fig. 2. The solid member 46 is provided with .a wrench socket 54 through which by use of a socket wrench, the entire threaded bolt assembly 40 may be secured to the plate 39 with the abrasive sheet 44 fixedly held, as above described, but with the contacting surfaces of members 46 and 48 capable of relative movement, which, however, cannot tighten with a binding or immovable effect.

A hand knob 56 is secured to the base member In which may be grasped by the hand of a user of this device and the device tipped forward, as

shown in Fig. 1, so that the front edge of the sanding disk 34 may engage the surface of the floor for sanding the same. A source of power, not shown, is adapted to actuate the pulley 24 for rotating the sanding disk 34.

When the sanding disk is being operated and the same is in contact with the floor and customary strains or stresses are imparted to the sanding disk 34, the sanding disk 34 and/or sandpaper 44 will impart the stress or strain to [the movably mounted member 48 and the member 48 will move relatively to the movement of the sanding disk 34, sandpaper 44, and member 46, and the relative movement of the member 48 with respect to the sandpaper and sanding disk prevents tightening damage to the fastening means.

When the sanding disk 34 is being rotated for sanding a defective floor, it will have a centrifugal action. Under normal operating conditions, the sandpaper 44 is maintained in operative position between sanding disk 34 and the floor, and the sanding disk 34, sandpaper 44, and the threaded v bolt assembly 46, all rotate as one unit. As before stated, where some unusual force or strain is imparted to the rotating disk 34, the hollow cone member 48 does not move as a unit with the sanding disk, but has a relative movement thereto, and as a result the sandpaper will not be damaged or torn at the point where the annular flange 5B of the hollow cone 48 maintains the sandpaper 44 in an engagement with the sanding disk 34.

I claim:

In a surface finishing device embodying a hub, a supporting disk secured to said hub, said disk having a relatively shallow central depression and a central aperture, a sheet of abrasive paper adapted to be positioned on the outer surface of the disk, of means for frictionally securing said sheet to said disk comprising an annular member having a frusto-cone shaped central depression for passage through the paper and entry into the aperture in said disk, said central portion being surrounded by a flat annular flange for holding a central portion of the paper within the shallow depressed portion of the disk, and a securing member having a threaded shank adapted to be secured in the hub, said securing member having a frusto-cone shaped head for closely engaging in a metal-to-metal contact substantially the entire interior surface of the frusto-cone shaped central depression of the annular member to substantially seal the same against entry of foreign matter and provide relative movement between said members.

WILLIAM P. HILGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,693,163 Schacht Nov. 27, 1928 1,725,361 Mall Aug. 20, 1929 1,778,471 Stratfcrd Oct. 14, 1930 2,114,966 Myers Apr. 19, 1938 2,114,967 Myers Apr. 19, 1938 2,172,407 Ramey Sept. 12, 1939 2,281,722 Smith May 5, 1942 

